Oil and gas production via fracking require the drilling of long horizontal wells, the fracturing of shale or siltstone, by various methods, and finally the treatment of the well to stabilize the fractures. This final step is typically accomplished by pumping a slurry of natural or manufactured sand product into the fractured zone to prop them open. Hence the term “proppant”. The packed bed must maintain a high degree of hydraulic conductivity as it must readily pass oil, gas and water.
A tradeoff exists for the smaller size range of proppants which are capable of stabilizing smaller fractures that generate a lot of the oil and gas, an advantage, but typically result in a lowered permeable pack, a drawback. The development of proppants that are small enough to prevent the healing of micro fractures (i.e. “micro-proppants”), but still demonstrate critical hydraulic conductivity as well as strength, represents both formidable challenge and a great opportunity.
This document describes a small diameter proppant, having high hydraulic conductivity and strength, from the hydraulic and mechanical classification of ponded Class F fly ash.